1. Field of the Invention
An automatic pilot for a sailboat that furnishes a selection of various modes of operation.
2. Description of the Prior Art
Generally, automatic pilots for motorized sea vessels follow a compass heading, and deviation from that compass heading is mechanically coupled to a rudder to correct for the deviation. However, if one were to use a compass heading automatic pilot for a sailboat, efficient operation of the sailboat might be impeded. This is so since the sails generally are oriented and trimmed to make best use of the wind, and if there are changes in the direction of the wind, the sailboat would not be wind driven at maximum efficiency. Thus, the sailboat would make better overall headway if it were allowed to deviate from the compass heading in order to make the most effective use of the sails. It would therefore be desirable if a sailboat were allowed to move in such a way that the wind angle relative to the heading of the sailboat is kept constant.
Generally, electrically or electro-mechanically controlled automatic pilots may tend to over-react to minor and sudden changes in wind or sea conditions, and tend to unnecessarily activate the rudder, thus causing the wearing of the steering mechanism or uneven or wobbly movement of the sailboat. Furthermore, continuous rapid change in direction of movement of the rudder may tend to impart an oscillatory movement to the sailboat. Still further, movement by the rudder in an automatic pilot system often causes an over-correction in the heading of the sailboat, which again results in the need for further correction, wherein such continuous correction resembles a damped oscillation.
One attempt to furnish an improved automatic pilot for the steering of a sailboat is shown in U.S. Pat. No. 3,685,478. This, however, does not provide a mode switching arrangement to enable different types of steering to be provided, these including a STEER mode, an OFF mode, a STANDBY mode, a WIND mode, and a COMPASS mode. Nor does this patent disclose a WIND mode which is capable of being altered to a COURSE CHANGE sub-mode. Nor does this patent disclose a COMPASS mode in which the sailboat is steered on a constant compass setting even if the required final rudder setting is one other than the initial rudder setting. Nor does this patent disclose a COURSE CHANGE sub-mode for the COMPASS mode. Nor does this patent disclose an automatic pilot which in the WIND mode or COMPASS mode can be made to furnish a command signal to enable a steersman to control the rudder under manual direction and yet maintain the correction signals furnished by the automatic pilot in its WIND mode and COMPASS mode so as to permit the sailboat to be steered by manual control and still retain the benefit of the WIND mode and COMPASS mode correction signals as well as to educate a steersman in the proper manner of handling a sailboat under either WIND mode conditions or COMPASS mode conditions.